Contents

Description

Some Runway Incursion incidents could have been prevented if controllers had had better means to detect that the runway was occupied at the time of issuing clearance to the next aircraft to use the runway. This article describes the typical scenarios for runway conflicts not being timely detected as well as the safety barriers that could prevent such situations or mitigate the consequences.

Operational Context

Aerodrome conflict scenarios are sometimes difficult to generalise due to the wide range of local variables. It might be difficult to separate the common (e.g. human error, safety barrier, etc.) from the specific (e.g. aerodrome layout, local equipment, local weather, etc.).
The following factors have the greatest potential to affect the availability and the effectiveness of the safety barriers:

Availability of surveillance information affects the likelihood of detection of RWY incursions and incorrect movement on the Manoeuvring Area. The level of ATC service may differ depending on equipage:

Integrated Tower Working Position (ITWP) using input and display of the ATC clearances in addition to surveillance to enable the use of early warnings to highlight any non-conformance to clearance

Visibility conditions from the Tower. The possibility of recognising potential threats in good time may differ depending upon visual impairment:

day/night

fog/mist

low cloud affecting high control towers

sunlight and glare during day

precipitation on windows

airport floodlighting during night, especially temporary work in progress

Runway configuration can influence how the operations on each runway can be affected by the operations on the adjacent ones and therefore how the specific barriers can be applied:

Multiple Parallel/Intersecting runways

Mixed mode/Single mode operations

Line of sight from the ATC Tower can differ based on the position, height, design, equipment and distance of the tower. These can restrict the direct view of the relevant part of the runways and manoeuvring area

Prevention and Mitigation Barriers

The following barriers, when deployed and employed correctly, are capable of alerting ATC in time to prevent runway incursions and ground conflicts and/or to prevent a ground collision in case of runway incursion or a ground safety event.

ATCO memory aids for issued (not issued) clearances

ATCO direct visual detection

ATCO visual detection using remote camera displays

ATCO detection and/or resolution following pilot/driver report

ATCO detection (e.g. of occupied runway) by use of basic Surface Movement Radar